FDA CRL - Merck & Co., Inc.

On June 28, 2013, the FDA issued a Complete Response Letter to Merck & Co., Inc. regarding its New Drug Application for Suvorexant, an insomnia medication. While the FDA acknowledged the drug's effectiveness, it determined the application could not be approved under the Federal Food, Drug, and Cosmetic Act due to significant safety concerns regarding the proposed dosage strengths. The agency identified dose-related risks for serious adverse effects, including suicidal ideation, daytime functional impairment that increases the risk of motor vehicle accidents, and a narcolepsy-like syndrome characterized by sleep paralysis and cataplexy. Additionally, concerns were raised regarding unconscious nighttime activity and hallucinations. The FDA concluded that while 30 mg and 40 mg doses are unsafe, a 10 mg dose is the appropriate starting point for most patients, and a 5 mg dose is necessary for patients with specific metabolic sensitivities. Because Merck did not submit manufacturing data for a 10 mg version or propose a 5 mg strength, the application was denied. To seek future approval, Merck must provide manufacturing data for the 10 mg dose, develop a 5 mg dosage form, submit a comprehensive safety update from all clinical trials, and revise product labeling to reflect these safety findings and lower recommended doses. The company has one year to address these deficiencies.